/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.jackrabbit.webdav.property;

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;

import org.apache.jackrabbit.webdav.xml.Namespace;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The <code>DavPropertySet</code> class represents a set of WebDAV property.
 */
public class DavPropertySet extends PropContainer {

	// ---------------------------------------------------------- Inner class
	// ---
	/**
	 * Implementation of a DavPropertyIterator that returns webdav property.
	 * Additionally, it can only return property with the given namespace.
	 */
	private class PropIter implements DavPropertyIterator {

		/** the namespace to match agains */
		private final Namespace namespace;

		/** the internal iterator */
		private final Iterator<DavProperty> iterator;

		/** the next property to return */
		private DavProperty next;

		/**
		 * Creates a new property iterator.
		 */
		private PropIter() {
			this(null);
		}

		/**
		 * Creates a new iterator with the given namespace
		 * 
		 * @param namespace
		 *            The namespace to match against
		 */
		private PropIter(Namespace namespace) {
			this.namespace = namespace;
			iterator = map.values().iterator();
			seek();
		}

		/**
		 * @see DavPropertyIterator#hasNext();
		 */
		public boolean hasNext() {
			return next != null;
		}

		/**
		 * @see DavPropertyIterator#next();
		 */
		public Object next() {
			return nextProperty();
		}

		/**
		 * @see DavPropertyIterator#nextProperty();
		 */
		public DavProperty nextProperty() throws NoSuchElementException {
			if (next == null) {
				throw new NoSuchElementException();
			}
			DavProperty ret = next;
			seek();
			return ret;
		}

		/**
		 * @see DavPropertyIterator#remove();
		 */
		public void remove() {
			throw new UnsupportedOperationException();
		}

		/**
		 * Seeks for the next valid property
		 */
		private void seek() {
			while (iterator.hasNext()) {
				next = iterator.next();
				if (namespace == null
						|| namespace.equals(next.getName().getNamespace())) {
					return;
				}
			}
			next = null;
		}
	}

	private static Logger log = LoggerFactory.getLogger(DavPropertySet.class);

	/**
	 * the set of property
	 */
	private final Map<DavPropertyName, DavProperty> map = new HashMap<DavPropertyName, DavProperty>();

	/**
	 * Adds a new property to this set.
	 * 
	 * @param property
	 *            The property to add
	 * 
	 * @return The previously assigned property or <code>null</code>.
	 */
	public DavProperty add(DavProperty property) {
		return map.put(property.getName(), property);
	}

	/**
	 * 
	 * @param pset
	 *            Properties to add
	 */
	public void addAll(DavPropertySet pset) {
		map.putAll(pset.map);
	}

	/**
	 * @param contentEntry
	 *            NOTE, that the given object must be an instance of
	 *            <code>DavProperty</code> in order to be successfully added to
	 *            this set.
	 * @return true if the specified object is an instance of
	 *         <code>DavProperty</code> and false otherwise.
	 * @see PropContainer#addContent(Object)
	 */
	@Override
	public boolean addContent(Object contentEntry) {
		if (contentEntry instanceof DavProperty) {
			add((DavProperty) contentEntry);
			return true;
		}
		log.debug("DavProperty object expected. Found: "
				+ contentEntry.getClass().toString());
		return false;
	}

	// ------------------------------------------------------< PropContainer
	// >---
	/**
	 * Checks if this set contains the property with the specified name.
	 * 
	 * @param name
	 *            The name of the property
	 * @return <code>true</code> if this set contains the property;
	 *         <code>false</code> otherwise.
	 * @see PropContainer#contains(DavPropertyName)
	 */
	@Override
	public boolean contains(DavPropertyName name) {
		return map.containsKey(name);
	}

	/**
	 * Retrieves the property with the specified <code>name</code>
	 * 
	 * @param name
	 *            The webdav property name of the property to retrieve
	 * 
	 * @return The desired property or <code>null</code>
	 */
	public DavProperty get(DavPropertyName name) {
		return map.get(name);
	}

	/**
	 * Retrieves the property with the specified <code>name</code> and the
	 * default WebDAV
	 * {@link org.apache.jackrabbit.webdav.DavConstants#NAMESPACE namespace}.
	 * 
	 * @param name
	 *            The name of the property to retrieve
	 * 
	 * @return The desired property or <code>null</code>
	 */
	public DavProperty get(String name) {
		return get(DavPropertyName.create(name));
	}

	/**
	 * Retrieves the property with the specified <code>name</code> and
	 * <code>namespace</code>.
	 * 
	 * @param name
	 *            The name of the property to retrieve
	 * @param namespace
	 *            The namespace of the property to retrieve
	 * 
	 * @return The desired property or <code>null</code>
	 */
	public DavProperty get(String name, Namespace namespace) {
		return get(DavPropertyName.create(name, namespace));
	}

	/**
	 * @see PropContainer#getContent()
	 */
	@Override
	public Collection<DavProperty> getContent() {
		return map.values();
	}

	/**
	 * @see PropContainer#getContentSize()
	 */
	@Override
	public int getContentSize() {
		return map.size();
	}

	/**
	 * Return the names of all properties present in this set.
	 * 
	 * @return array of {@link DavPropertyName property names} present in this
	 *         set.
	 */
	public DavPropertyName[] getPropertyNames() {
		Set<DavPropertyName> keySet = map.keySet();
		return keySet.toArray(new DavPropertyName[keySet.size()]);
	}

	/**
	 * @see PropContainer#isEmpty()
	 */
	@Override
	public boolean isEmpty() {
		return map.isEmpty();
	}

	/**
	 * Returns an iterator over all property in this set.
	 * 
	 * @return An iterator over {@link DavProperty}.
	 */
	public DavPropertyIterator iterator() {
		return new PropIter();
	}

	/**
	 * Returns an iterator over all those property in this set, that have the
	 * indicated <code>namespace</code>.
	 * 
	 * @param namespace
	 *            The namespace of the property in the iteration.
	 * 
	 * @return An iterator over {@link DavProperty}.
	 */
	public DavPropertyIterator iterator(Namespace namespace) {
		return new PropIter(namespace);
	}

	/**
	 * Removes the indicated property from this set.
	 * 
	 * @param name
	 *            The webdav property name to remove
	 * 
	 * @return The removed property or <code>null</code>
	 */
	public DavProperty remove(DavPropertyName name) {
		return map.remove(name);
	}

	/**
	 * Removes the property with the specified <code>name</code> and the default
	 * WebDAV {@link org.apache.jackrabbit.webdav.DavConstants#NAMESPACE
	 * namespace}.
	 * 
	 * @param name
	 *            The name of the property to remove
	 * 
	 * @return The removed property or <code>null</code>
	 */
	public DavProperty remove(String name) {
		return remove(DavPropertyName.create(name));
	}

	/**
	 * Removes the property with the specified <code>name</code> and
	 * <code>namespace</code> from this set.
	 * 
	 * @param name
	 *            The name of the property to remove
	 * @param namespace
	 *            The namespace of the property to remove
	 * 
	 * @return The removed property or <code>null</code>
	 */
	public DavProperty remove(String name, Namespace namespace) {
		return remove(DavPropertyName.create(name, namespace));
	}
}
